The basic plot: The British Prime Minister dies and the heads of state of many countries, including America, must go to the funeral in London. Little do they know that an arms dealer/terrorist whose family was maimed/killed in a US drone attack a couple of years earlier has elaborately planned, with the help of a UK mole, to kill them all (and blow up lots of famous landmarks). Only the US President survives, thanks to the dogged determination of Secret Service agent, Mike Banning (Butler).